The invention relates to a device for the decontamination of water, particularly removal of heavy metals and/or arsenic and/or their compounds.
The elimination of particularly heavy metals and/or arsenic and/or their compounds from water in order to produce drinking water is currently possible only in an unsatisfactory manner. The contamination levels of drinking water with, for example, arsenic—especially in regions with similarly polluted groundwater—generally lie at or above the permitted values. Numerous devices for purifying water are already known; however, they are not effective in removing arsenic DE 33 36 460 A1, for example, describes a method and a device for purifying water by means of electrolysis, wherein the water to be purified is conducted past electrodes made of bivalent or trivalent metals of different polarities. Iron or aluminium is preferably used as the electrode material.
Furthermore, an arrangement for treating polluted water by means of electrolysis is known, in which alternating electrodes made from steel and aluminium are combined with one another (DE 43 15 117 A1), or iron and/or aluminium electrodes are used (DE 43 29 272). The use of aluminium electrodes, however, results in a high pH-value, which has an especially negative effect on the removal of arsenic.
More advantageous in this regard is the pH-value in the solutions disclosed in DE 694 16 698 T2, WO 99/11577 A1, DE-OS 2 201 070, and JP 7-256272 A, which use carbon dioxide. The CO2 is produced by using graphite electrodes or added from the outside during electrolysis. Admittedly, however, the combination of electrodes used for attaining a low pH-value, and thereby a high reduction of arsenic, is not optimal. Extremely disadvantageous in all of the devices of the prior art is the fixed, immovable arrangement of the electrodes. This causes their handling, especially during the repair and cleaning of the device, to be more difficult.
Accordingly, there is a need for improvements to water-treating apparatus that accommodate easier cleaning and repair, and maintain efficient contaminant removal.